From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 429C83EDAB5 for ; Fri, 6 Mar 2026 15:57:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772812649; cv=none; b=nZN2wRFIF4F4Baj7QYdeghbPv9KWgvkxrkNPw5Rl5pWZfUcpvUwETC9oipqKQSLG/0N2C1tlo5ajPi2lFhctMXcTzxx+vvEAjhkvlCqODNtPhV3snnttMGaFj6BMaUqQ2YoVup9laOI0r41Yw5FaMeIZgw7j/tPz5Pc0j/E4KBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772812649; c=relaxed/simple; bh=uLd9V1oCpPRWtIo1XizCv09BniqJ8HX1YepTkcjMXh4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=e/gqYA/ckPcoeEbMIIjC5jmZQ6JZ7vMkrgA5K+ppRFnIaelIhrGYIVnijs7s/+S9fZ7SQv0jfFYoEsJT9KK1+vOCQEaK0IRDBDR7ArYL4yKjQFBhzavOkQ0Uwxxe5rJDOeGUP7heexW6W9DbUFceS6G7RcuaN7D1b12IxeNuNhk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=DP6UKx7M; arc=none smtp.client-ip=209.85.221.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DP6UKx7M" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-439ae28f5fcso4452754f8f.2 for ; Fri, 06 Mar 2026 07:57:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772812646; x=1773417446; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=1VJwwrxymdAZuyNsFopMLfzW51d6bGAIMUJLL86H4+U=; b=DP6UKx7MwA//RudFySkPKdjiyGguCG48uZvZfLhT+P6onvmPv1h2qjvfmLYLbScN+y NzqvG+OrYG0A2lKUOL8leyWD9eu3Sqd+ID1uskG/P+A5csNL3OJceiUw6QcKPLUOap+b pyPEJrAT9wREu2ZsrkCGaDkJZGOrNLeHgZMbsV/6r4uyjGuKdgoUf01Vnt/MzpPN6DD/ iNbm8rmK5UETckPsE7EB2GnF23/1VKBBUZQY+ezPmwqrwve2xuI9wgYeZQA5nAbxwCvx A2Worhk23YfAc7MZczhs9eSbZUIRs9FkQJ/UdTclh6bElHnIS1G40nKzZmmMLhnOfEho lW3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772812646; x=1773417446; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=1VJwwrxymdAZuyNsFopMLfzW51d6bGAIMUJLL86H4+U=; b=Ib+TaHgHHZ9fBZxx9/lHzVPykwpWmWiQfNztZvJGftsnbyAMjovJGi7nQ3YF0boGEy y5qGP5ABBA3tGqJBkGg7eqsYr+e4B0ua+kteSealsPZGD7kAf1Hi/SA1y+gqD1bfykh6 EY6svW0X/V5hX7nDivEg158asMzHD/J8HnDhxKm5pssqoFqV1wTPcSEgi9pRHfE21Q3H SnNZUsNS6KY84+ajxql1WQQGayEB8DJiExTn7vEJ0ZBkqSX1pZEK9xXZ7RTbkcz/qQ2C TmXClHO8Y6uaRJEihEIvJC9ZYHzVpjNW/DOiSk8TBev6Mj/jWDfipokPSF0BI5mRRvJM 3vdA== X-Gm-Message-State: AOJu0Yx3c5MfG3EA5ZeiMHZXHxuyl4nVmHEIz129c/EizQjwHpTXPDpn dQSExg+gS81jaEye8xmqXPURLmuAFIn8v1tIIZ0nCo9/E7qw7TSwFkwfR7ytvEFFVCBobFb9HA= = X-Received: from wrbcm14.prod.google.com ([2002:a5d:5f4e:0:b0:439:b8a5:41be]) (user=ardb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:420b:b0:439:a958:434b with SMTP id ffacd0b85a97d-439da31dbf6mr4340230f8f.2.1772812645563; Fri, 06 Mar 2026 07:57:25 -0800 (PST) Date: Fri, 6 Mar 2026 16:57:11 +0100 In-Reply-To: <20260306155703.815272-12-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260306155703.815272-12-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=8782; i=ardb@kernel.org; h=from:subject; bh=jGYP0/YOGkv3IJMXLQNb+76CSu4ibyPhkWVRrJnk7UU=; b=owGbwMvMwCVmkMcZplerG8N4Wi2JIXPVz+BDxzlYs5S/eFz1rVL1W9D7QVpxYfvfxUzOQqbf7 yyZNF2qo5SFQYyLQVZMkUVg9t93O09PlKp1niULM4eVCWQIAxenAExkfSwjw9HXytFe0jkcxXMV vC6xdxa9v66VtndDbYONM5vJ3PLXuYwMb+fqZp08vKjeyKj5YFzMVMZDS3nu3V1axyr85ZNLk/l WfgA= X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260306155703.815272-19-ardb+git@google.com> Subject: [RFC PATCH 6/9] x86/efi: Do not rely on EFI_MEMORY_RUNTIME bit and avoid entry splitting From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linux-efi@vger.kernel.org, x86@kernel.org, Ard Biesheuvel , "Mike Rapoport (Microsoft)" , Benjamin Herrenschmidt Content-Type: text/plain; charset="UTF-8" From: Ard Biesheuvel Now that efi_mem_reserve() has been updated to rely on RSRV_KERN memblock reservations, it is no longer needed to mark memblock reserved regions as EFI_MEMORY_RUNTIME. This means that it is no longer needed to split existing entries in the EFI memory map, removing the need to re-allocate/copy/remap the entire EFI memory map on every call to efi_mem_reserve(). So drop this functionality - it is no longer needed. Note that, for the time being, this requires the E820 map to be consulted when deciding whether or not an entry with the EFI_MEMORY_RUNTIME cleared needs to be preserved in the runtime map or not. However, this will be superseded and removed by a subsequent patch, which combines the map compaction with the actual freeing, in which case the freeing logic can answer this question directly. Signed-off-by: Ard Biesheuvel --- arch/x86/include/asm/efi.h | 4 - arch/x86/platform/efi/memmap.c | 138 -------------------- arch/x86/platform/efi/quirks.c | 60 +-------- 3 files changed, 5 insertions(+), 197 deletions(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 51b4cdbea061..b01dd639bf62 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -396,10 +396,6 @@ extern int __init efi_memmap_alloc(unsigned int num_entries, struct efi_memory_map_data *data); extern int __init efi_memmap_install(struct efi_memory_map_data *data); -extern int __init efi_memmap_split_count(efi_memory_desc_t *md, - struct range *range); -extern void __init efi_memmap_insert(struct efi_memory_map *old_memmap, - void *buf, struct efi_mem_range *mem); extern enum efi_secureboot_mode __x86_ima_efi_boot_mode(void); diff --git a/arch/x86/platform/efi/memmap.c b/arch/x86/platform/efi/memmap.c index 023697c88910..8ef45014c7e7 100644 --- a/arch/x86/platform/efi/memmap.c +++ b/arch/x86/platform/efi/memmap.c @@ -110,141 +110,3 @@ int __init efi_memmap_install(struct efi_memory_map_data *data) __efi_memmap_free(phys, size, flags); return 0; } - -/** - * efi_memmap_split_count - Count number of additional EFI memmap entries - * @md: EFI memory descriptor to split - * @range: Address range (start, end) to split around - * - * Returns the number of additional EFI memmap entries required to - * accommodate @range. - */ -int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range) -{ - u64 m_start, m_end; - u64 start, end; - int count = 0; - - start = md->phys_addr; - end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1; - - /* modifying range */ - m_start = range->start; - m_end = range->end; - - if (m_start <= start) { - /* split into 2 parts */ - if (start < m_end && m_end < end) - count++; - } - - if (start < m_start && m_start < end) { - /* split into 3 parts */ - if (m_end < end) - count += 2; - /* split into 2 parts */ - if (end <= m_end) - count++; - } - - return count; -} - -/** - * efi_memmap_insert - Insert a memory region in an EFI memmap - * @old_memmap: The existing EFI memory map structure - * @buf: Address of buffer to store new map - * @mem: Memory map entry to insert - * - * It is suggested that you call efi_memmap_split_count() first - * to see how large @buf needs to be. - */ -void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf, - struct efi_mem_range *mem) -{ - u64 m_start, m_end, m_attr; - efi_memory_desc_t *md; - u64 start, end; - void *old, *new; - - /* modifying range */ - m_start = mem->range.start; - m_end = mem->range.end; - m_attr = mem->attribute; - - /* - * The EFI memory map deals with regions in EFI_PAGE_SIZE - * units. Ensure that the region described by 'mem' is aligned - * correctly. - */ - if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) || - !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) { - WARN_ON(1); - return; - } - - for (old = old_memmap->map, new = buf; - old < old_memmap->map_end; - old += old_memmap->desc_size, new += old_memmap->desc_size) { - - /* copy original EFI memory descriptor */ - memcpy(new, old, old_memmap->desc_size); - md = new; - start = md->phys_addr; - end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1; - - if (m_start <= start && end <= m_end) - md->attribute |= m_attr; - - if (m_start <= start && - (start < m_end && m_end < end)) { - /* first part */ - md->attribute |= m_attr; - md->num_pages = (m_end - md->phys_addr + 1) >> - EFI_PAGE_SHIFT; - /* latter part */ - new += old_memmap->desc_size; - memcpy(new, old, old_memmap->desc_size); - md = new; - md->phys_addr = m_end + 1; - md->num_pages = (end - md->phys_addr + 1) >> - EFI_PAGE_SHIFT; - } - - if ((start < m_start && m_start < end) && m_end < end) { - /* first part */ - md->num_pages = (m_start - md->phys_addr) >> - EFI_PAGE_SHIFT; - /* middle part */ - new += old_memmap->desc_size; - memcpy(new, old, old_memmap->desc_size); - md = new; - md->attribute |= m_attr; - md->phys_addr = m_start; - md->num_pages = (m_end - m_start + 1) >> - EFI_PAGE_SHIFT; - /* last part */ - new += old_memmap->desc_size; - memcpy(new, old, old_memmap->desc_size); - md = new; - md->phys_addr = m_end + 1; - md->num_pages = (end - m_end) >> - EFI_PAGE_SHIFT; - } - - if ((start < m_start && m_start < end) && - (end <= m_end)) { - /* first part */ - md->num_pages = (m_start - md->phys_addr) >> - EFI_PAGE_SHIFT; - /* latter part */ - new += old_memmap->desc_size; - memcpy(new, old, old_memmap->desc_size); - md = new; - md->phys_addr = m_start; - md->num_pages = (end - md->phys_addr + 1) >> - EFI_PAGE_SHIFT; - md->attribute |= m_attr; - } - } -} diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index e72e8b23598e..8a4a0c6b64bc 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -239,63 +239,9 @@ EXPORT_SYMBOL_GPL(efi_query_variable_store); * buggy implementations we reserve boot services region during EFI * init and make sure it stays executable. Then, after * SetVirtualAddressMap(), it is discarded. - * - * However, some boot services regions contain data that is required - * by drivers, so we need to track which memory ranges can never be - * freed. This is done by tagging those regions with the - * EFI_MEMORY_RUNTIME attribute. - * - * Any driver that wants to mark a region as reserved must use - * efi_mem_reserve() which will insert a new EFI memory descriptor - * into efi.memmap (splitting existing regions if necessary) and tag - * it with EFI_MEMORY_RUNTIME. */ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size) { - struct efi_memory_map_data data = { 0 }; - struct efi_mem_range mr; - efi_memory_desc_t md; - int num_entries; - void *new; - - if (efi_mem_desc_lookup(addr, &md) || - md.type != EFI_BOOT_SERVICES_DATA) { - pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr); - return; - } - - if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) { - pr_err("Region spans EFI memory descriptors, %pa\n", &addr); - return; - } - - size += addr % EFI_PAGE_SIZE; - size = round_up(size, EFI_PAGE_SIZE); - addr = round_down(addr, EFI_PAGE_SIZE); - - mr.range.start = addr; - mr.range.end = addr + size - 1; - mr.attribute = md.attribute | EFI_MEMORY_RUNTIME; - - num_entries = efi_memmap_split_count(&md, &mr.range); - num_entries += efi.memmap.nr_map; - - if (efi_memmap_alloc(num_entries, &data) != 0) { - pr_err("Could not allocate boot services memmap\n"); - return; - } - - new = early_memremap_prot(data.phys_map, data.size, - pgprot_val(pgprot_encrypted(FIXMAP_PAGE_NORMAL))); - if (!new) { - pr_err("Failed to map new boot services memmap\n"); - return; - } - - efi_memmap_insert(&efi.memmap, new, &mr); - early_memunmap(new, data.size); - - efi_memmap_install(&data); e820__range_update(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED); e820__update_table(e820_table); } @@ -509,8 +455,12 @@ void __init efi_unmap_boot_services(void) for_each_efi_memory_desc(md) { if (!(md->attribute & EFI_MEMORY_RUNTIME) && (md->type == EFI_BOOT_SERVICES_CODE || - md->type == EFI_BOOT_SERVICES_DATA)) + md->type == EFI_BOOT_SERVICES_DATA) && + !e820__mapped_any(md->phys_addr, + md->phys_addr + md->num_pages * EFI_PAGE_SIZE, + E820_TYPE_RESERVED)) { continue; + } memcpy(new_md, md, efi.memmap.desc_size); new_md += efi.memmap.desc_size; -- 2.53.0.473.g4a7958ca14-goog